The manipulation of fluids for administration to a patient in hospital and medical settings involves the use of drug access systems that typically include a sealed inflatable container, commonly referred to as an intravenous (IV) bag. The IV bag is used to store a primary liquid such as plasma, blood, saline, or other types of medicinal solutions. When fluids are to be introduced into a patient intravenously, an IV bag is suspended above the patient on a portable hanger stand. Through a series of tubes and connectors, the fluid within the IV bag is delivered from the IV bag to the patient.
FIG. 1 illustrates a partial perspective view of a traditional IV bag 100. The IV bag includes a sealed inlet or injection port 102 and an outlet port 104 for the transfer of fluids to and from the IV bag, respectively. The inlet port 102 permits the introduction of a secondary fluid, such as a drug, into the IV bag for mixing with the primary fluid. The outlet port 104 permits the transfer of the primary solution in the IV bag to the patient via tubes and connectors.
To seal the contents of the bag, the inlet port 102 typically includes a septum 106 compressively affixed within the interior opening of the inlet port to prevent the flow of fluid out of the bag. The septum 106 may be of continuous construction or made with a pre-fabricated slit that remains closed until penetrated. In either case, the septum is sufficiently resilient so as to permit penetration of the septum with a sharp device such as a syringe needle for the transfer of fluids into the IV bag.
Another example of a sharp device for penetrating a septum within an inlet port is a spiked connector. One type of spiked connector is a dual-spiked connector comprising a housing having a conduit extending from one spike to the other. The first spike is open-ended, in which the conduit communicates with the ambient. The second spike, at the opposite end of the connector, is closed such that the conduit is not in communication with the ambient. This closed-end tip is designed to break away and is used to penetrate the IV bag through the inlet port. At the first end, the open-ended spike is used to penetrate a drug vial containing a secondary fluid. By placing this dual-spiked connector between a drug vial and the IV bag, a secondary fluid can be introduced into the IV bag and mixed with the primary fluid therein.
As a discrete pre-fabricated component, such a dual-spiked connector does not permit fluid flow therethrough because at least one spike includes a closed, break-away tip. However, upon penetration of the closed spike tip through the inlet port of the IV bag, fluid communication between the secondary fluid container and the bag may be established by breaking off the break-away tip while the tip is within the interior of the IV bag. Once the tip is broken, the conduit of the connector permits the flow of fluid in the internal fluid conduit from the drug vial to the interior of the IV bag. Disadvantageously, the break-away tip floats in the IV bag during the administration of the primary and secondary fluids to the patient through the outlet port. Should the break-away tip become lodged in the outlet port of the IV bag, the flow of the primary and secondary fluids to the patient may be stopped or dramatically reduced, endangering the health of a patient. Moreover, because the mixed solution in the IV bag is visible to the patient, the existence of the floating foreign object (spike tip) in the fluid may be psychologically troubling to the patient.
Another type of dual-spiked connector for introducing a secondary fluid into an IV bag is one that eliminates the break-away tip. With this alternative connector, the conduit is in communication with the ambient at both spiked ends. Instead of a breakaway tip, however, this alternative connector employs a plug centrally positioned within the internal conduit to prevent the flow of fluid therethrough until the medical practitioner so desires. After both spikes of the connector are in place, i.e., both have penetrated their respective medical containers, the medical practitioner applies an external compressive force to the plug by squeezing the IV bag. The force applied dislodges the plug, whereby the plug is forced into the secondary fluid container (drug vial).
The use of a push-away plug also presents problems. For example, it has been proven difficult, if not costly, to manufacture a conduit plug that reliably performs as designed. If the conduit plug is made too small, the plug does not exert sufficient frictional force against the interior walls of the internal conduit. Under those circumstances, the ambient pressure from the primary fluid itself may dislodge the primary plug prematurely, causing leakage of fluid intended for a patient. Alternatively, if the conduit plug is too large, the compressive force that is necessary to dislodge the plug is too great. Under those circumstances, the force applied externally to the IV bag may adversely compromise the structural integrity of the bag, again causing life-sustaining fluid to leak.
With either of the above connectors, an inherent problem exists in that once fluid flow is established, it cannot be stopped. That is because neither connector is adapted to control the fluid flow therethrough. Moreover, the configuration of the connectors is such that a fluid-control valve cannot be readily attached to the exposed spike end of the connector. Valves that exist to control the flow of medicinal fluids into an IV bag, such as that shown in U.S. Pat. No. 5,694,686, have male luer fittings that are not designed to connect to a spike (e.g. the CLAVE® 1000 connector manufactured by ICU Medical, Inc. of San Clemente, Calif. or the pre-slit Injection Site manufactured by McGaw Inc. of Irvine, Calif.) Thus, a device to permit an IV bag to be placed in fluid communication with a wide range of commercially available connectors is needed.
Another problem with the connectors identified above is that manufacturing costs are high. Typically, the connectors are injection molded. To generate the interior conduit of the connector housing, a core pin is used to define the surface of the interior conduit. Due to the extremely high temperatures used in the molding process, there is a tendency of the core pin to float within the liquified housing material during the molding process, creating non-uniform wall thickness, which is unacceptable. Thus, the rejection rate is high, driving up the costs of manufacture.
There is, therefore, a need for a drug access system configured to eliminate break-away or floating parts, to reduce the cost of part manufacture, and to expand the use of connectors to which an IV bag may be attached.